No Black Hole Or Magnetic Monopole: Tunguska Really Was a Meteor

davide-nature writes "The mysterious blast that flattened 2,000 square km of a remote Siberian forest in 1908 has been blamed on the most bizarre causes, such as an exotic elementary particle left over from the Big Bang, a black hole or, of course, aliens, including in the double-episode 'Tunguska' of The X-Files. But a new analysis of tiny rock samples suggests that a more mundane explanation — a meteor exploding in the atmosphere — may be the right one. The blast is estimated to have packed between 3 and 5 megatons, 10 times the energy of the meteor that exploded over Russia earlier this year."